An Assistant Service Director shall be appointed by the Mayor and confirmed by Council until his successor is appointed. He shall supervise the improvement and repair of streets, avenues, alleys, landings, market houses, bridges, viaducts, sidewalks, sewers, drains, ditches, culverts, streams and watercourses. He shall also supervise sewage disposal, garbage and refuse collection and the lighting, sprinkling and cleaning of all public places, and he shall have the custody and care of all tools, implements and trucks used in connection with his duties. He shall perform such other duties consistent with the nature of his office as Council may require. He shall have such assistants and may employ such labor as may be authorized by ordinance.